I recently read the answer to a question regarding the difference between a tree and a spanning tree. The following is the link: Difference between a tree and spanning tree?!
Now we know that the total possible trees for a graph = n^(n-2). Therefore, for a graph containing 4 nodes, number of trees possible = 4^(4-2) = 16
Looking at the picture, it is clear that all of the 16 trees contain all 4 nodes present in the original graph, i.e. there is not a single tree with less than 4 nodes. But the answer provided in the question to the link shared above says otherwise. I am pretty confused by now. Any response would be greatly appreciated.